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Lodash _.indexOf


The lodash _.indexOf method is a popular utility function used in JavaScript development. It is part of the popular Lodash library, which is a collection of helper functions that simplify common programming tasks.

The _.indexOf method is used to find the index of a specified value in an array. It returns the index of the first occurrence of the value in the array if it exists, or -1 if it does not exist.

Here is the syntax for the _.indexOf method:

_.indexOf(array, value, fromIndex)
  • array: The array to search.
  • value: The value to search for.
  • fromIndex: The optional starting index to search from. If not provided, the search starts from index 0.

The _.indexOf method can be used with arrays of any data type, including numbers, strings, and objects. It can also be used with arrays of mixed data types.

Here are some examples of how to use the _.indexOf method:

// Search for a string in an array
const arr1 = ['apple', 'banana', 'cherry'];
const index1 = _.indexOf(arr1, 'banana'); // index1 = 1

// Search for a number in an array
const arr2 = [1, 2, 3, 4, 5];
const index2 = _.indexOf(arr2, 3); // index2 = 2

// Search for an object in an array
const arr3 = [{ id: 1, name: 'John' }, { id: 2, name: 'Jane' }, { id: 3, name: 'Bob' }];
const obj = { id: 2, name: 'Jane' };
const index3 = _.indexOf(arr3, obj, 0); // index3 = 1

The _.indexOf method is a very useful utility function that simplifies searching for values in an array. It can be used in a wide variety of scenarios, particularly when dealing with large datasets.